全文获取类型
收费全文 | 667篇 |
免费 | 51篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 25篇 |
妇产科学 | 21篇 |
基础医学 | 60篇 |
口腔科学 | 26篇 |
临床医学 | 144篇 |
内科学 | 82篇 |
皮肤病学 | 5篇 |
神经病学 | 35篇 |
特种医学 | 17篇 |
外科学 | 45篇 |
综合类 | 2篇 |
一般理论 | 3篇 |
预防医学 | 166篇 |
眼科学 | 6篇 |
药学 | 53篇 |
中国医学 | 4篇 |
肿瘤学 | 23篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 19篇 |
2019年 | 31篇 |
2018年 | 19篇 |
2017年 | 30篇 |
2016年 | 24篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 36篇 |
2012年 | 49篇 |
2011年 | 63篇 |
2010年 | 30篇 |
2009年 | 26篇 |
2008年 | 53篇 |
2007年 | 46篇 |
2006年 | 36篇 |
2005年 | 40篇 |
2004年 | 38篇 |
2003年 | 37篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有718条查询结果,搜索用时 390 毫秒
1.
Kevin O'Brien Jean Wright Frances Conboy YeWeng Sanjie Nicky Mandall Stephen Chadwick Ivan Connolly Paul Cook David Birnie Mark Hammond Nigel Harradine David Lewis Cathy McDade Laura Mitchell Alison Murray Julian O'Neill Mike Read Stephen Robinson Dai Roberts-Harry Jonathan Sandler Ian Shaw 《American journal of orthodontics and dentofacial orthopedics》2003,124(3):234-43; quiz 339
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant. 相似文献
2.
BACKGROUND: Menstrual disorders are a common presentation in primary care. Wide variations in management as well as discordance between patient and practitioners in relation to presenting problems have been described. AIMS: To explore the model of menstrual disorders used by practitioners in practice. DESIGN OF STUDY: Semi-structured interviews with primary care practitioners. SETTING: One inner London health authority area. METHOD: Constant comparative analysis. RESULTS: Medical practitioners were critical of the guidance provided by gynaecological definitions and texts. Practitioners put more emphasis on defining normality than on defining disorder. Practitioners used a wide range of criteria to judge their patients' complaints and decide on a course of action. Female practitioners had access to personal and professional experience and used this to develop an understanding of women's complaints. Male practitioners in particular were limited by problems in discussing menstruation in detail. Because of the difficulties in assessing patient history, other non-gynaecological factors such as patient age and consulting behaviour informed practitioners' judgements. CONCLUSION: This study draws attention to practitioners' problems in using current definitions of menstrual disorders. The combination of unhelpful medical definitions, lack of standards of normality and difficulties in discussing menstruation resulted in individual practitioners making judgements in idiosyncratic ways. In the absence of a useful gynaecological model, practitioners develop individual, often subjective and gendered models to use in practice. 相似文献
3.
Markov transition models are frequently used to model disease progression. The authors show how the solution to Kolmogorov's forward equations can be exploited to map between transition rates and probabilities from probability data in multistate models. They provide a uniform, Bayesian treatment of estimation and propagation of uncertainty of transition rates and probabilities when 1) observations are available on all transitions and exact time at risk in each state (fully observed data) and 2) observations are on initial state and final state after a fixed interval of time but not on the sequence of transitions (partially observed data). The authors show how underlying transition rates can be recovered from partially observed data using Markov chain Monte Carlo methods in WinBUGS, and they suggest diagnostics to investigate inconsistencies between evidence from different starting states. An illustrative example for a 3-state model is given, which shows how the methods extend to more complex Markov models using the software WBDiff to compute solutions. Finally, the authors illustrate how to statistically combine data from multiple sources, including partially observed data at several follow-up times and also how to calibrate a Markov model to be consistent with data from one specific study. 相似文献
6.
7.
8.
Bonnie R. Valgaeren Bart Pardon Evy Goossens Stefanie Verherstraeten Sophie Roelandt Leen Timbermont Nicky Van Der Vekens Sabrina Stuyvaert Linde Gille Laura Van Driessche Freddy Haesebrouck Richard Ducatelle Filip Van Immerseel Piet Deprez 《Toxins》2015,7(7):2586-2597
Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin. 相似文献
9.
10.